[SOLVED] Print an arrow into a TAChart
lazarus / 55-TAChart

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donnie · 2016-12-05 12:55

Hi there,
I have drawn an arrow from a start point A(x0,y0 let's say 0,0) to an
end point B(x1,y1). The shape of the arrow shows that direction from A
to B (A->B). The code I used is this:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i var Arrow1:
TFieldSeries; .....begin        Line1 := TLineSeries.Create(self);  
     Chart1.AddSeries(Line1);           Arrow1 :=
TFieldSeries.Create(self);      Chart1.AddSeries(Arrow1);       for i
:= Low(Array1) to High(Array1) do        Line1.AddXY(Array1[i].y,
Array2[i].y); // Array1 and Array2 have the same Length      
Arrow1.AddVector(Array1[High(Array1)].y/2, Array2[High(Array2)].y/2,
Array1[High(Array1)].y, Array2[High(Array2)].y, '', $0000FF);     
Arrow1.Pen.Width:=3;      Arrow1.Arrow.BaseLength :=
ArrowPView1.Arrow.Length;    end; 
As I want the arrow to start from (0,0) and end to the my last point I
use the
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
Arrow1.AddVector(Array1[High(Array1)].y/2, Array2[High(Array2)].y/2,
Array1[High(Array1)].y, Array2[High(Array2)].y, '', $0000FF);When I
draw the chart everything seems ok. But when I print the chart the
arrow get too much bigger.
I believe that the problem must be the GraphToImage(DoublePoint(x1,
y1)).
I also need to draw that arrow above all lines in the TAChart (so its
Zposition must be the bigger).

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wp · 2016-12-05 13:33

Could you post a little demo showing the issue? Only pas, lfm, lpi and
lpr files packed into common zip, please. And remove everything which
is not needed to demonstrate the bug.

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donnie · 2016-12-05 14:27

Yes after a little hour I manage to keep the necessary.
Click Draw first and after that Print.

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wp · 2016-12-05 15:13

Please try r53560. I had to modify your demo since I don't have two
required packages (lz_report, lz_tachart - what are these?), but I
think it is working now.

P.S.
Seems to be CodeTyphoon...
In this case my patch does not help you immediately. Open
]"]>Blockedltiseries.pas, go to procedure TFieldSeries.DrawVector.
After the line "if FArrow.Visible" there's an assignment to len.
Divide this calculation by ADrawer.Scale(1). The entire DrawVector
method should read:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TFieldSeries.DrawVector(ADrawer: IChartDrawer;  AStartPt, AEndPt:
TDoublePoint; APen: TPen);var  p1, p2: TPoint;  arr: TChartArrow; 
len: Double;begin  p1 := ParentChart.GraphToImage(AStartPt);  p2 :=
ParentChart.GraphToImage(AEndPt);  ADrawer.Pen := APen; 
ADrawer.Line(p1.x, p1.y, p2.x, p2.y);  if FArrow.Visible then begin  
len := sqrt(sqr(p2.x - p1.x) + sqr(p2.y - p1.y)) * 0.01 /
ADrawer.Scale(1);    // Be aware that the drawer scales pixels. But
the arrow length here is    // already at the correct size!    arr :=
TChartArrow.Create(nil);    arr.Assign(FArrow);    arr.SetOwner(nil);
 // avoid repainting due to next commands    arr.BaseLength :=
round(FArrow.BaseLength * len);    arr.Length := round(FArrow.Length *
len);    arr.Width := round(FArrow.Width * len);    arr.Draw(ADrawer,
p2, arctan2(p2.y-p1.y, p2.x-p1.x), APen);    arr.Free;  end;end;

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donnie · 2016-12-06 08:04

Yeap, exactly that!!!
Now the print is perfect.
You are the master of the chart my friend.
Thanks once again wp!!!